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Table of Contents
Vol. 34, No. 2, 2010
Issue release date: February 2010
Section title: Original Paper
Free Access
Neuroepidemiology 2010;34:123–129
(DOI:10.1159/000274804)

Geographic Variation in One-Year Recurrent Ischemic Stroke Rates for Elderly Medicare Beneficiaries in the USA

Allen N.B.a, f · Holford T.R.b · Bracken M.B.c · Goldstein L.B.d · Howard G.e · Wang Y.a · Lichtman J.H.a
Divisions of aChronic Disease Epidemiology and bBiostatistics, Department of Epidemiology and Public Health, and cCenter for Perinatal, Pediatric and Environmental Epidemiology, Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, Conn., dDepartment of Medicine (Neurology), Duke Stroke Center, Center for Clinical Health Policy Research, Duke University and Durham VAMC, Durham, N.C., eDepartment of Biostatistics, School of Public Health, University of Alabama at Birmingham, Birmingham, Ala., and fDepartment of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Ill., USA
email Corresponding Author

Abstract

Background: While geographic disparities in stroke mortality are well documented, there are no data describing geographic variation in recurrent stroke. Accordingly, we evaluated geographic variations in 1-year recurrent ischemic stroke rates in the USA with adjustment for patient characteristics. Methods: One-year recurrent stroke rates for ischemic stroke (International Classification of Diseases, 9th Revision codes 433, 434 and 436) following hospital discharge were calculated by county for all fee-for-service Medicare beneficiaries from 2000 to 2002. The rates were standardized and smoothed using a bayesian conditional autoregressive model that was risk-standardized for patients’ age, gender, race/ethnicity, prior hospitalizations, Deyo comorbidity score, acute myocardial infarction, congestive heart failure, diabetes, hypertension, dementia, cancer, chronic obstructive pulmonary disease and obesity. Results: The overall 1-year recurrent stroke rate was 9.4% among 895,916 ischemic stroke patients (mean age: 78 years; 56.6% women; 86.6% White, 9.7% Black and 1.2% Latino/Hispanic). The rates varied by geographic region and were highest in the South and in parts of the West and Midwest. Regional variation was present for all racial/ethnic subgroups and persisted after adjustment for individual patient characteristics. Conclusions: Almost 1 in 10 hospitalized ischemic stroke patients was readmitted for an ischemic stroke within 1 year. There was heterogeneity in recurrence patterns by geographic region. Further work is needed to understand the reasons for this regional variability.

© 2010 S. Karger AG, Basel


  

Key Words

  • Stroke, recurrent
  • Small-area analysis
  • Variation, geographic
  • Recurrence

References

  1. Lloyd-Jones D, Adams R, Carnethon M, et al: Heart disease and stroke statistics – 2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2009;119:480–486.
  2. Samsa GP, Bian J, Lipscomb J, et al: Epidemiology of recurrent cerebral infarction: a Medicare claims-based comparison of first and recurrent strokes on 2-year survival and cost. Stroke 1999;30:338–349.
  3. Pickle LW, Mungiole M, Gillum RF: Geographic variation in stroke mortality in Blacks and Whites in the United States. Stroke1997;28:1639–1647.
  4. Lanska DJ, Kryscio R: Geographic distribution of hospitalization rates, case fatality, and mortality from stroke in the United States. Neurology 1994;44:1541–1550.
  5. El-Saed A, Kuller LH, Newman AB, et al: Geographic variations in stroke incidence and mortality among older populations in four US communities. Stroke 2006;37:1975–1979.
  6. Casper M, Nwaise I, Croft J, et al: Atlas of Stroke Hospitalizations among Medicare Beneficiaries. Atlanta, US Department of Health and Human Services, Centers for Disease Control and Prevention, 2008.
  7. Deyo RA, Cherkin DC, Ciol MA: Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613–619.
  8. Coull AJ, Rothwell PM: Underestimation of the early risk of recurrent stroke: evidence of the need for a standard definition. Stroke 2004;35:1925–1929.
  9. Sarti C, Stegmayr B, Tolonen H, et al: Are changes in mortality from stroke caused by changes in stroke event rates or case fatality? Results from the WHO MONICA Project. Stroke 2003;34:1833–1840.
  10. Bonita R, Anderson CS, Broad JB, et al: Stroke incidence and case fatality in Australasia: a comparison of the Auckland and Perth population-based stroke registers. Stroke 1994;25:552–557.
  11. Hill ME, Rosenwaike I: The Social Security Administration’s Death Master File: the completeness of death reporting at older ages. Soc Secur Bull2001;64:45–51.

    External Resources

  12. Besag J, York J, Mollie A: Bayesian image restoration, with two applications in spatial statistics. Ann Inst Stat Math 1991;43:1–59.

    External Resources

  13. Lunn D, Thomas A, Best N, Spiegelhalter D: WinBUGS – a Bayesian modelling framework: concepts, structure, and extensibility. Stat Comput 2000;10:325–337.

    External Resources

  14. Petty GW, Brown RD Jr, Whisnant JP, et al: Survival and recurrence after first cerebral infarction: a population-based study in Rochester, Minnesota, 1975 through 1989. Neurology 1998;50:208–216.
  15. Sacco RL, Shi T, Zamanillo MC, et al: Predictors of mortality and recurrence after hospitalized cerebral infarction in an urban community: the Northern Manhattan Stroke Study. Neurology 1994;44:626–634.
  16. Eriksson SE, Olsson JE: Survival and recurrent strokes in patients with different subtypes of stroke: a fourteen-year follow-up study. Cerebrovasc Dis 2001;12:171–180.
  17. Lisabeth LD, Smith MA, Brown DL, et al: Ethnic differences in stroke recurrence. Ann Neurol 2006;60:469–475.
  18. Matsumoto N, Whisnant JP, Kurland LT, et al: Natural history of stroke in Rochester, Minnesota, 1955 through 1969: an extension of a previous study, 1945 through 1954. Stroke 1973;4:20–29.
  19. Sacco RL, Wolf PA, Kannel WB, et al: Survival and recurrence following stroke. The Framingham Study. Stroke1982;13:290–295.
  20. Ostchega Y, Dillon CF, Hughes JP, et al: Trends in hypertension prevalence, awareness, treatment, and control in older U.S. adults: data from the National Health and Nutrition Examination Survey 1988 to 2004. J Am Geriatr Soc 2007;55:1056–1065.
  21. Moroney JT, Bagiella E, Paik MC, et al: Risk factors for early recurrence after ischemic stroke: the role of stroke syndrome and subtype. Stroke 1998;29:2118–2124.
  22. Hillen T, Coshall C, Tilling K, et al: Cause of stroke recurrence is multifactorial: patterns, risk factors, and outcomes of stroke recurrence in the South London Stroke Register. Stroke 2003;34:1457–1463.
  23. Ruland S, Richardson D, Hung E, et al: Predictors of recurrent stroke in African Americans. Neurology 2006;67:567–571.
  24. Gillum RF, Ingram DD: Relation between residence in the southeast region of the United States and stroke incidence. The NHANES I Epidemiologic Follow-Up Study. Am J Epidemiol 1996;144:665–673.
  25. Howard G: Why do we have a stroke belt in the southeastern United States? A review of unlikely and uninvestigated potential causes. Am J Med Sci 1999;317:160–167.
  26. Perry HM, Roccella EJ: Conference report on stroke mortality in the southeastern United States. Hypertension 1998;31:1206–1215.
  27. Howard G, Prineas R, Moy C, et al: Racial and geographic differences in awareness, treatment, and control of hypertension: the Reasons for Geographic and Racial Differences in Stroke Study. Stroke 2006;37:1171–1178.
  28. Voeks JH, McClure LA, Go RC, et al: Regional differences in diabetes as a possible contributor to the geographic disparity in stroke mortality: the Reasons for Geographic and Racial Differences in Stroke Study. Stroke 2008;39:1675–1680.
  29. Cushman M, Cantrell RA, McClure LA, et al: Estimated 10-year stroke risk by region and race in the United States: geographic and racial differences in stroke risk. Ann Neurol 2008;64:507–513.
  30. Tirschwell DL, Longstreth WT Jr: Validating administrative data in stroke research. Stroke 2002;33:2465–2470.
  31. Leibson CL, Naessens JM, Brown RD, et al: Accuracy of hospital discharge abstracts for identifying stroke. Stroke 1994;25:2348–2355.
  32. Fisher ES, Whaley FS, Krushat WM, et al: The accuracy of Medicare’s hospital claims data: progress has been made, but problems remain. Am J Public Health 1992;82:243–248.
  33. Benesch C, Witter DM Jr, Wilder AL, et al: Inaccuracy of the International Classification of Diseases (ICD-9-CM) in identifying the diagnosis of ischemic cerebrovascular disease. Neurology 1997;49:660–664.
  34. Kiyota Y, Schneeweiss S, Glynn RJ, et al: Accuracy of Medicare claims-based diagnosis of acute myocardial infarction: estimating positive predictive value on the basis of review of hospital records. Am Heart J 2004;148:99–104.
  35. Quan H, Li B, Saunders LD, et al: Assessing validity of ICD-9-CM and ICD-10 administrative data in recording clinical conditions in a unique dually coded database. Health Serv Res 2008;43:1424–1441.
  36. Williams GR: Incidence and characteristics of total stroke in the United States. BMC Neurol 2001;1:2.

  

Author Contacts

Judith Lichtman
Yale University School of Medicine
PO Box 208034
New Haven, CT 06520-8034 (USA)
Tel. +1 203 785 3025, Fax +1 203 785 6980, E-Mail judith.lichtman@yale.edu

  

Article Information

Received: July 12, 2009
Accepted: November 10, 2009
Published online: January 13, 2010
Number of Print Pages : 7
Number of Figures : 2, Number of Tables : 2, Number of References : 36
Additional supplementary material is available online - Number of Parts : 1

  

Publication Details

Neuroepidemiology

Vol. 34, No. 2, Year 2010 (Cover Date: February 2010)

Journal Editor: Feigin V.L. (Auckland)
ISSN: 0251-5350 (Print), eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Copyright / Drug Dosage / Disclaimer

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Abstract

Background: While geographic disparities in stroke mortality are well documented, there are no data describing geographic variation in recurrent stroke. Accordingly, we evaluated geographic variations in 1-year recurrent ischemic stroke rates in the USA with adjustment for patient characteristics. Methods: One-year recurrent stroke rates for ischemic stroke (International Classification of Diseases, 9th Revision codes 433, 434 and 436) following hospital discharge were calculated by county for all fee-for-service Medicare beneficiaries from 2000 to 2002. The rates were standardized and smoothed using a bayesian conditional autoregressive model that was risk-standardized for patients’ age, gender, race/ethnicity, prior hospitalizations, Deyo comorbidity score, acute myocardial infarction, congestive heart failure, diabetes, hypertension, dementia, cancer, chronic obstructive pulmonary disease and obesity. Results: The overall 1-year recurrent stroke rate was 9.4% among 895,916 ischemic stroke patients (mean age: 78 years; 56.6% women; 86.6% White, 9.7% Black and 1.2% Latino/Hispanic). The rates varied by geographic region and were highest in the South and in parts of the West and Midwest. Regional variation was present for all racial/ethnic subgroups and persisted after adjustment for individual patient characteristics. Conclusions: Almost 1 in 10 hospitalized ischemic stroke patients was readmitted for an ischemic stroke within 1 year. There was heterogeneity in recurrence patterns by geographic region. Further work is needed to understand the reasons for this regional variability.

© 2010 S. Karger AG, Basel


  

Author Contacts

Judith Lichtman
Yale University School of Medicine
PO Box 208034
New Haven, CT 06520-8034 (USA)
Tel. +1 203 785 3025, Fax +1 203 785 6980, E-Mail judith.lichtman@yale.edu

  

Article Information

Received: July 12, 2009
Accepted: November 10, 2009
Published online: January 13, 2010
Number of Print Pages : 7
Number of Figures : 2, Number of Tables : 2, Number of References : 36
Additional supplementary material is available online - Number of Parts : 1

  

Publication Details

Neuroepidemiology

Vol. 34, No. 2, Year 2010 (Cover Date: February 2010)

Journal Editor: Feigin V.L. (Auckland)
ISSN: 0251-5350 (Print), eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Article / Publication Details

First-Page Preview
Abstract of Original Paper

Received: 7/12/2009
Accepted: 11/10/2009
Published online: 1/13/2010
Issue release date: February 2010

Number of Print Pages: 7
Number of Figures: 2
Number of Tables: 2

ISSN: 0251-5350 (Print)
eISSN: 1423-0208 (Online)

For additional information: http://www.karger.com/NED


Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

References

  1. Lloyd-Jones D, Adams R, Carnethon M, et al: Heart disease and stroke statistics – 2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation 2009;119:480–486.
  2. Samsa GP, Bian J, Lipscomb J, et al: Epidemiology of recurrent cerebral infarction: a Medicare claims-based comparison of first and recurrent strokes on 2-year survival and cost. Stroke 1999;30:338–349.
  3. Pickle LW, Mungiole M, Gillum RF: Geographic variation in stroke mortality in Blacks and Whites in the United States. Stroke1997;28:1639–1647.
  4. Lanska DJ, Kryscio R: Geographic distribution of hospitalization rates, case fatality, and mortality from stroke in the United States. Neurology 1994;44:1541–1550.
  5. El-Saed A, Kuller LH, Newman AB, et al: Geographic variations in stroke incidence and mortality among older populations in four US communities. Stroke 2006;37:1975–1979.
  6. Casper M, Nwaise I, Croft J, et al: Atlas of Stroke Hospitalizations among Medicare Beneficiaries. Atlanta, US Department of Health and Human Services, Centers for Disease Control and Prevention, 2008.
  7. Deyo RA, Cherkin DC, Ciol MA: Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol 1992;45:613–619.
  8. Coull AJ, Rothwell PM: Underestimation of the early risk of recurrent stroke: evidence of the need for a standard definition. Stroke 2004;35:1925–1929.
  9. Sarti C, Stegmayr B, Tolonen H, et al: Are changes in mortality from stroke caused by changes in stroke event rates or case fatality? Results from the WHO MONICA Project. Stroke 2003;34:1833–1840.
  10. Bonita R, Anderson CS, Broad JB, et al: Stroke incidence and case fatality in Australasia: a comparison of the Auckland and Perth population-based stroke registers. Stroke 1994;25:552–557.
  11. Hill ME, Rosenwaike I: The Social Security Administration’s Death Master File: the completeness of death reporting at older ages. Soc Secur Bull2001;64:45–51.

    External Resources

  12. Besag J, York J, Mollie A: Bayesian image restoration, with two applications in spatial statistics. Ann Inst Stat Math 1991;43:1–59.

    External Resources

  13. Lunn D, Thomas A, Best N, Spiegelhalter D: WinBUGS – a Bayesian modelling framework: concepts, structure, and extensibility. Stat Comput 2000;10:325–337.

    External Resources

  14. Petty GW, Brown RD Jr, Whisnant JP, et al: Survival and recurrence after first cerebral infarction: a population-based study in Rochester, Minnesota, 1975 through 1989. Neurology 1998;50:208–216.
  15. Sacco RL, Shi T, Zamanillo MC, et al: Predictors of mortality and recurrence after hospitalized cerebral infarction in an urban community: the Northern Manhattan Stroke Study. Neurology 1994;44:626–634.
  16. Eriksson SE, Olsson JE: Survival and recurrent strokes in patients with different subtypes of stroke: a fourteen-year follow-up study. Cerebrovasc Dis 2001;12:171–180.
  17. Lisabeth LD, Smith MA, Brown DL, et al: Ethnic differences in stroke recurrence. Ann Neurol 2006;60:469–475.
  18. Matsumoto N, Whisnant JP, Kurland LT, et al: Natural history of stroke in Rochester, Minnesota, 1955 through 1969: an extension of a previous study, 1945 through 1954. Stroke 1973;4:20–29.
  19. Sacco RL, Wolf PA, Kannel WB, et al: Survival and recurrence following stroke. The Framingham Study. Stroke1982;13:290–295.
  20. Ostchega Y, Dillon CF, Hughes JP, et al: Trends in hypertension prevalence, awareness, treatment, and control in older U.S. adults: data from the National Health and Nutrition Examination Survey 1988 to 2004. J Am Geriatr Soc 2007;55:1056–1065.
  21. Moroney JT, Bagiella E, Paik MC, et al: Risk factors for early recurrence after ischemic stroke: the role of stroke syndrome and subtype. Stroke 1998;29:2118–2124.
  22. Hillen T, Coshall C, Tilling K, et al: Cause of stroke recurrence is multifactorial: patterns, risk factors, and outcomes of stroke recurrence in the South London Stroke Register. Stroke 2003;34:1457–1463.
  23. Ruland S, Richardson D, Hung E, et al: Predictors of recurrent stroke in African Americans. Neurology 2006;67:567–571.
  24. Gillum RF, Ingram DD: Relation between residence in the southeast region of the United States and stroke incidence. The NHANES I Epidemiologic Follow-Up Study. Am J Epidemiol 1996;144:665–673.
  25. Howard G: Why do we have a stroke belt in the southeastern United States? A review of unlikely and uninvestigated potential causes. Am J Med Sci 1999;317:160–167.
  26. Perry HM, Roccella EJ: Conference report on stroke mortality in the southeastern United States. Hypertension 1998;31:1206–1215.
  27. Howard G, Prineas R, Moy C, et al: Racial and geographic differences in awareness, treatment, and control of hypertension: the Reasons for Geographic and Racial Differences in Stroke Study. Stroke 2006;37:1171–1178.
  28. Voeks JH, McClure LA, Go RC, et al: Regional differences in diabetes as a possible contributor to the geographic disparity in stroke mortality: the Reasons for Geographic and Racial Differences in Stroke Study. Stroke 2008;39:1675–1680.
  29. Cushman M, Cantrell RA, McClure LA, et al: Estimated 10-year stroke risk by region and race in the United States: geographic and racial differences in stroke risk. Ann Neurol 2008;64:507–513.
  30. Tirschwell DL, Longstreth WT Jr: Validating administrative data in stroke research. Stroke 2002;33:2465–2470.
  31. Leibson CL, Naessens JM, Brown RD, et al: Accuracy of hospital discharge abstracts for identifying stroke. Stroke 1994;25:2348–2355.
  32. Fisher ES, Whaley FS, Krushat WM, et al: The accuracy of Medicare’s hospital claims data: progress has been made, but problems remain. Am J Public Health 1992;82:243–248.
  33. Benesch C, Witter DM Jr, Wilder AL, et al: Inaccuracy of the International Classification of Diseases (ICD-9-CM) in identifying the diagnosis of ischemic cerebrovascular disease. Neurology 1997;49:660–664.
  34. Kiyota Y, Schneeweiss S, Glynn RJ, et al: Accuracy of Medicare claims-based diagnosis of acute myocardial infarction: estimating positive predictive value on the basis of review of hospital records. Am Heart J 2004;148:99–104.
  35. Quan H, Li B, Saunders LD, et al: Assessing validity of ICD-9-CM and ICD-10 administrative data in recording clinical conditions in a unique dually coded database. Health Serv Res 2008;43:1424–1441.
  36. Williams GR: Incidence and characteristics of total stroke in the United States. BMC Neurol 2001;1:2.